Oh. XVII.] INSEOTIVOBOUS PLANTS. 319 



movement; whereas no movement was caused if the card 

 remained separated from the tip by a layer of the liquid gum. 

 The fact also of thicker and thinner bits of card attached on 

 opposite sides of the same root by shellac, causing movement 

 in one direction, has to be explained. You often speak of the 

 tip having been injured ; but externally there was no sign of 

 injury : and when the tip was plainly injured, the extreme part 

 became curved towards the injured side. I can no more 

 believe that the tip was injured by the bits of card, at least 

 when attached by gum-water, than that the glands of Drosera 

 are injured by a particle of thread or hair placed on it, or that 

 the human tongue is so when it feels any such object. 



About the most important subject in my book, namely 

 circumnutation, I can only say that I feel utterly bewildered 

 at the difference in our conclusions ; but I could not fully 

 understand some parts which my son Francis will be able to 

 translate to me when he returns home. The greater part of 

 your book is beautifully clear. 



Finally, I wish that I had enough strength and spirit to 

 commence a fresh set of experiments, and publish the results, 

 with a full recantation of my errors when convinced of them ; 

 but I am too old for such an undertaking, nor do I suppose 

 that I shall be able to do much, or any more, original work. 

 I imagine that I see one possible source of error in your 

 beautiful experiment of a plant rotating and exposed to a 

 lateral light. 



With high respect, and with sincere thanks for the kind 

 manner in which you have treated me and my mistakes, I 

 remain, 



My dear Sir, yours sincerely. 



Insectivorous Plants. 



In the summer of 1860 he was staying at the house of his 

 sister-in-law, Miss Wedgwood, in Ashdown Forest whence he 

 wrote (July 29, 1860), to Sir Joseph Hooker : — 



" Latterly I have done nothing here ; but at first I amused 

 myself with a few observations on the insect-catching power 

 of Drosera : * and I must consult you some time whether my 

 * twaddle ' is worth communicating to the Linnean Society." 



In August he wrote to the same friend : — 



" I will gratefully send my notes on Drosera when copied 



* The common sun-dew. 



